1. Field of the Invention
This invention relates to ground fault interrupter apparatus of the differential transformer type and more particularly it pertains to a ground fault detector in side-by-side position with a multi-pole circuit breaker structure.
2. Description of the Prior Art
A standard circuit breaker of multi-pole construction has elements for sensing mainly thermal overload and magnetic overload currents. The ability of a multi-pole circuit breaker to transfer magnetic action from one pole to another when one of the conditions such as thermal overload or magnetic overload takes place to effect a disconnect in the other poles that are mutually coupled is used in constructing a multi-pole breaker. There is a need for a ground fault circuit breaker capable of such action when sensing a ground fault current flow on any of the poles and thereby effecting a disconnect on the mutually coupled poles. This action must be accomplished in a direct drive manner to maintain the necessary speeds required for personnel protection. An enhancement of this speed is absolutely necessary and is not achieved in a standard breaker for personnel protection.
In a ground fault multi-pole circuit breaker the essential criteria of a single pole ground fault circuit breaker is utilized. However, it can be inadequate because of new operating restrictions that are present in a multi-pole application. The multi-pole ground fault circuit breaker must work across 120/240 voltages which upon loss of any leg or pole must not impair the ability of the electronic section to sense and protect human beings when they are in a dangerous ground fault contact. Additionally, the ability to detect a grounded neutral condition must be present when either of the poles has power lost on it.